Method of and means for manufacturing artificial silk

ABSTRACT

211,691. H÷lken, M. Feb. 13, 1923. Apparatus for making filaments.-Each spinning head of a multiple - unit plant for spinning artificial silk from cuprammonia-cellulose solutions employing large spinning apertures, is associated with an apportioning-device such as a gear-wheel pump, for the supply of solution; working in this manner more uniform and finer threads are obtained, and the drawing-out of the threads proceeds more quickly. The threads are spun into the precipitating-liquid, are stretched therein and if desired, during their passage through the air, and are finally treated with hardening-liquid. In the plant shown, the pumps c are mounted on brackets g clamped to the main supply pipe a; the pumps are mounted on pivots l, k so that they may be rocked to gear with a main driving shaft u, and the pivots are bored for the passage of the cellulose solution. The spinning heads b are connected to the delivery side of the pumps by jointed arms o, one of the joints o&lt;1&gt; of which being of the character of a cock so that on raising the arm the flow of liquid is cut off.

M. HGLKEN. JR I METHOD OF AND MEANS FOR MANUFACTURING ARTIFICIAL SILKSept. 6,1927.

2 Sheets-Sheet 1 Filed Jan. 25. 1923 6 1927., sept M. HOLKEN, JR

METHOD OF AND MEANS FOR MANUFACTURING ARTIFICIAL SILK 2 Shets-Sheet 2Filed Jan. 25. 1925 Fig.2

[Hi e22 far Patented Sept. 6, i927.

MARTIN HbLKEN, JR., 0F BARMEN, GERMANY.

METHOD OF AND MEANS FOR MANUFACTURING ARTIFICIAL SILK.

Application filed January 25, 1923, Serial No. 614,826, and in GermanyJuly 12, 1920.

My invention relates to the so-ca'lled stretching spinning method forthe manufacture of artificial silk from cellulose solutions, and moreespecially solutions of cupric oxide ammonia cellulose, in which processthe comparatively thick threads issuing froin the spinning rose arefirst conducted through a liquid, the so-called precipitating liquidwhich flows in the direction of the thread pull and serves to wash outthe solvent; the threads are stretched while being conducted throughthis liquid and, may be, also through an air space forming acontinuation of their way through the llquid. In other words, thethreads are firstdrawn out to the desired degree of fineness, and thentreated with a: hardening liquid for stiffening them. 7

With the known methods of this kind the I spinning solution is conducteddirectly to the sprinklers from a common conduit which is under pressureand has merely a shut-ofi cock inserted into it. Generally a pluralityof such sprinklers (about 4:0) arearranged in one machine. Inconsequence thereof, the thickness of the threads produced in a machinenot only va'ries more or less at different times, but also the threadsproduced by the individual sprinklers differ greatly. Owing to this, thethickness or fineness of the threadsiis always more or less a matter ofchance, and artificial silk manufactured after the stretching spinningmethod and being marked for a' certain degree of fineness always showsgreat deviations from this degree of fineness.

I have now ascertained that artificial silkthreads of a uniformfineness, the degree of which may be determined in advance, may beobtained from all spinning heads or sprinklers of a machine, if thesprays which receive the solution from a common supply pipe are fed fromthis pipe not directly, but by way of apportioning'devices, of which oneis provided for each spray, for instance a rotary gear or cog-wheel pumpwhich renders the supply independent of the pressure existing. in saidpipe. By this means not only thedesired uniformity of the fineness of gthe threads is obtained, but further striking advantages resnlt fromthis manner of 'o.p eration, in that on the one side the fineness of thethreads is considerably improved and on the other side the-drawingofi ofthe threads proceeds considerably more quickly, whereby the output ofthread is greatly increased. Besides, owing ,to the greater tures.

stretching of the threads, also their appearance and their quality isimproved so that cupric oxide ammonia silk thus made forms a novelproduct which is apt toanswer the highestrequirements as to uniformity,fineness, resemblance to silk, and also as regards washing.

I am aware that providing a pump for each spinning head is already knownin connection with such methods of producing artificial silk wherethe-heads or sprinklers have very small apertures and where, therefore,a separate pump is required to force the spinning liquid through thesmall aper- I-Ieretofore, however, individual pumps or other force feeddevices or controllers for expressing the solution through or governingits flow to the respective spinnaret-tes have not been employed in themanufacture of cuprammonium silk by the stretch-spinning method, inwhich the spinnarettes are provided with comparatively large spinningapertures of awell known standard size of 0.8 min. or 1 mm. In suchstretch-spinning method as heretofore carried out, where the use of aforce-feed pump is not necessary, because of the large size of thespinnarette apertures, the solution has always been supplied under.gravity pressure to thespinnarettes which are connected to a commonsupply pipe leading from 'a tank or reservoir, the flow of the solutionthrough the pipe and thence to the spinnarettes being controlled by anordinary hand valve. As the spinnarettes'arelocated at differentdistances from the source of supply, the pressure of the solutionsupplied to the difl'erent spinnarettes varies, as a result of whichirregularities of expression occur, causing the production of filamentsvaryingin size so that a thread of constantly uniform diameter can notbe-formed. This condition is aggraavated by unavoidable pulsations inthe supply pipe caused at times by viscosity differences in thesolution, and

by the clogging of spinnarette apertures pressed, 'so that a thread 0irregular diameter will be. formed, or the thread will have roughsurfaces due to the presence of thickened portions, or both conditionswill exist, making such thread diflicult to work on textile machines andreducing its commercial value. For these reasons the ordinarystretch-spinning process yields only aboutsixty ercent 60%) of perfectthread. I have iscovere that by the employment in .a stretch-spinningapparatus of what are known in the'viscose and other artificial silkarts as rotary (geared pumps, one for each spinnarette, an by the use ofsuch so-called pumps as measuring and flow controlling devices, theoperation of the spinning apparatus may be so changed as to overcome theabove-noted defects in the ordinary stretch-spinning method, and so asto provide a new and improved method enabling, to. a very high degree,thread of a constantly uniform smoothness of surface and predetermineddiameter ,to be produced. By the use of toothed gearing for driving allthe flow controllers of a spinning machine from a source of-power at apredetermined speed at all times and under all conditions, I also securea novel and improved expressing action, for the expression with absolutecertainty through the apertures of each spinnarette of a fixed volume ofthe solution per unit of time constantly proportionate for a rate'offiow through the spinnarette apertures for continually producingfilaments of aggregate dimensions when combined to form a continuouslysmooth thread of continuously predetermined and unvarying diameter. Theflow controllers as employed in my method and apparatus further serve asbaflies to protect the volume .of solution which is being expressed fromfluctuations of pressure in the supply pipe, thereby obtaining a greateruniformity of operation in the expressing action.

To carry this method into practice, the spinning device as hithertoemployed in connection with the cupric oxide ammonia method may be used,provided that each spinning head or sprinkler is combined with a feeddevice or controller which may consist, for instance, of a rotary gearedpump as employed in connection with the older method above mentioned.The connection of the spinning spray with the supply pipe is, however,not efiected as hitherto, by a piece of rubber hose, but by anarticulated double arm permitting of a parallel displacement and, thus,if necessary, of removing the spinning sprinkler from, and putting itagain on, the glass cylinder containing the in Figure 3.

1, 2, 3 are three spinning devices arranged side by side and providedeach with a spinning head or sprinkler having a sieve-bottom throughwhich the cellulose solution is distributed. Each of the spinning headsI), b is arranged at the upper end of a glass cylinder 11 containing arather long glass funnel w, the purpose of which is to conduct downwardsthe threads issuing from the spinning spray, together with theprecipitating liquor. This liquor is introduced at the bottom of thecylinder 1' through a pipe m and rises in the annular space between thewalls of the cylinder and of the funnel until reaching the upper edge ofthis latter when it flows down into and through it with increasing speedand takes the bundle of threads with it, segregating at the same timethe solvent therefrom. The threads issuing from the spinning heads 6, bare comparatively thick, but on their way through the precipitatingliquid and, may be, also on an air way forming a continuation thereofare stretched and then rendered solid by being treated with a hardeningliqu d; finally, they are wound up either already during the treatmentwith the hardening liquid or there: after. Stretching the threads iseffected in most cases by the pull of the winding-up device and may beassisted, if desired, by the.

precipitating liquor which flows in the direction of the pull. The meansfor treating the threads withthe hardening liquid and the winding updevice, are not illustrated in the drawings, as they do not form part ofthis invention and may be of any known kind.

, The spinning devices, of which aplurality is arranged side by side andwhich form, in their entirety, the thread producing machine, are fedfrom a common pipe (2 with the cellulose solution which is apportionedto each device by means of a rotary geared controller such as a rotarygear pump a of known construction which is connected on its suction sidewith. the general feed pipe 0: and on the delivery side with thespinning spray b of the associate spinning devices 1 or 2 or 3.

The controllers or rotary gear pumps are all of equal size an'd haveequal outputs independent of the pressure in the feed pipe 02. They aredriven by a common shaft u with which they are coupledv by pairs ofcogwheels t and u having all the same ratio of gearing so that arisetheir numbers of revolution in the unit of time-are the same. Inconsequence thereof all spinning devlces 1, 2, "3 forming parts of amachine receive exactly corresponding quantities of the cel- 5 lulosesolution in the unit of time. The

quantity of cellulose solution apportioned to the spinning devices maybe altered in common for all devices and in exact agreement by changingthe number eOf IBVOl11 tions of the shaft M which may be effected by anysuitable means, such, for instance,

as geared wheels or friction discs or the like.

I have abstained from illustrating such a means in the drawings becauseit is well I5 known and does not form part of this invention. a

In this manner the several spinning devices are simultaneously anduniformly regulated, in the manner necessary to obtain '1 the desiredfineness of the threads.

The operation is as follows: 7 The so-called rotary gear pumps 0, whilegenerally similar in construction to rotary gear pumps of the typeemployed in viscose 'and other artificial silk methods using aforce-feed expression, have normally a ferent action in this apparatus.They serve under all normal conditions, as measuring devices for feedingthe solution in definite volumes to the spinnarettes, and as baflies forprotecting the'portions'of solution fed to the spinnarettes forexpression from'any varia- ";tions of pressure in the supply conduit a.As each pump or controller is introduced in a flow passage between theconduit 1% and a spinnarette b, it divides the flow passage into intakeand discharge portions. The solution in the conduit a is normally undera predetermined gravity pressure, and the pressure is the same in theintake portion of the passage on the suction side of the pump. Thispressure is normally higher than that which exists in the discharge sideof the flow passage. between the pump and spinnarette,

cause of thecomparatively large size of the spinnarette apertures andthe fact that the rapidly flowing precipitating liquid in" the chamber1' and funnel w produces a partial vacuum in said chamber on thedischarge side of the spinnarette and a combined suction pull on thesolution and drawing pull on the expremed filaments. Because of thelarge size of the spinnarette apertures, the pressure force required forexpression is not normally greater than that of the gravity force actingon the solution plus the suction and drawing pulls. The pumps '0, aredriven by the gears tu .from thedrive shaft u at such speed as todeliver a,

measured volume of solution, per unit of time, to each spinnarette. Theamount of solution delivered to each spinnarette ,by each pump in anydefinite period of time is exactly equal to the maximum amount of.

"solution which may be expressed through rette apertures.

the spinnarette a ertures under such normal working con itions, in thesame period of time, when said apertures are unclogged or unconstrictedand fully open. During such action, and at all other times, the volumeof solution in such discharge portion of the flow passage will beseparated from the solution in the conduit a and protected from anyvariations of pressure occurring in said conduit (1. The volume of fluidbeing expressed will thereforeuhav'e' an even and regular flow rate,without jets or pulsations, and consequently will constantly fill. thespinnarette apertures for the expression of filaments of a continuouslyregular and predetermined size. At all times, therefore, when theapertures are unconstricted, filaments of an unvarying and predetermineddiameter and free from defects will be formed, which when'combined willbe con-- stantly of roper aggregate dimensions to form a continuouslysmooth thread of a continuously predetermined and unvarying diameter.The pressure in the discharge side of the flow passage may vary more orless,

5 however, under normal working conditions of the spinnarette, due tounavoidable changes in the Viscosit of the solution, so that in theevent of t e solution being of higher than normal viscosity, the pumpmay act with a forcing pressure because of the resistance to flow of thesolution, and thereby ina'intain \the rate of'maximum expressingcapacity of the spinnarette. In the event of the constriction orreduction in size of spinnarette apertures by particles of impurities inthe solution, the resistance to fiow of the solution thereby inducedwill cause a back pressure to be thrown upon the pump. In this case, thepump becomes a low pressure force feed expressing device, operatingwithjust suflicient expressing force to dislodge the impurities and clearthe spinna- Ordinarily this is effected immediately when the expressionforce is in creased by the action of the pump when. a resistance is setup, before any apparent variations in the expression action can occur,

so that no undesirable change in the size of the filaments or theformation of. nodules or other thickened portions will occur. If,however, one or more spinnarette apertures should remain constricted, orbe completely clogged, and shouldnot. be cleared by the induced lowforce pressure of the pump before the filaments previously expressedfrom the clogged openings are broken under -,the stretchingactiori, thena new expressing action is set up. Under this new expressing action,whereby the back pressure of the solution on the pump isfu'rtherincreased, the pump exerts a higher forcing pressure, with the resultthat the solution Wlll be slightly condensed and the entire amountof thesolution discharged through the clear apertures. Necessarily in suchoperation, with apertures fully clog ed or partly clogged, or both, thenumber 0 the filaments expressed will be reduced, and some or all of thefilaments may be of greater than predetermined size, and others of lessthan predetermined cause an established low workingpressure of the pumpgenerally results in an lnstantaneous clearance of the apertures, but,even under conditions of partial or complete clogging of some of theapertures of a spinnarette, the same amount of solution will be 1 formedthread will appear.

continuously expressed and a thread of continuously uniform diameterproduced. Where for an infinitesimal period of time cessation of flow ofsolution through a constricted aperture occurs, causing a slightthickening in the filament expressed, the thickened portion will bereduced by the stretching action and, as such thickened portion of afilament will be enveloped in the other filaments no undue irregularityof surface or material increase of thickness of the It will be apparentthat, as each pump is immutably driven by toothed gearing from the driveshaft, no slippage and change of action .of the pump can occur when backpressure is thrown upon the pump, consequently the same amount ofsolution will and must always be expressed through the apertures of aspinnaiette. By so gearing up each pump, and all pumps of the series,all the pumps operate to invariably supply the same amount of solutionto the different, spinnarettes fed thereby, and as a result nodifference in expressing ratio between the diflerent spinnarettes of themachine, or between the spinnarettes and the stretching and windingdevices, can occur. The regularity of action of the spinnarettes, as aresult of such measuring and fiow controlling and compensating forcefeed actions of the pumps is such that, in actual working prac tice,ninety percent of the amount of i thread produced is thread of perfectlyuniform diameter and of high quality which brings the highest marketprice. Losses due to amount of imperfect thread reduced are also greatlyreduced. As before escribed, the construction is such that anyspinnarette and its feed controller may be thrown into and out of actionat will independently of the other spinnarettes and controllers andwithout affectin the operation of the spinnarettes and contrdllers keptin service. Consequently in any way by resulting pressure changes in thesupply conduit a. A very valuable and important'advantage of theinvention, due to this novel flow control and expressing action is thatspinnarettes with discharge apertures of much greater than normaldiameter may be used. I have in practice used spinnarette apertures ofas large a size as 3 mm. with perfect success. As a result, the volumeof production of a machine may be greatly increased without increasedworking costs.

Each of the rotary geared pumps 0 0 may be turned around an axle lyingin parallel to the driving shaft u in order to disengage the respectivecog-Wheels and bring the respective pump to a standstill. Each pump is.for the purpose in question, provided with two pivots Z and is supportedin two bearings g and h forming projecting parts of the front half fof abipartite clip (1 f clamped to the feed pipe a in immediate proximity tothe respective spinning device. The pivots Z and k are arrangedco-axially with thesuction aperture and the delivery aperture of therespective pump and are provided with channels connecting the pump onthe one side with the pipe at and on the other side with the spinningdevice. The journal Z which lies in the direction of flow of thecellulose solu tion before the pump is constructed to form at the sametime a shut-off cock and is provided for this purpose with an angularbore 71, the radial leg of which is connected, at a certain position ofthis journal, with a longitudinal bore 5 provided in the bearing g. Thejournal 1 is of conical shape and is rotatable in the correspondinglyshaped transverse bore of the bearing g, and its outer end is providedwith a square projection which is designed to receive a wrench by whichthe journal may be turned in order to disconnect the bores i and i. Theother journal is is also provided with an angular bore m and is madestationary in the transverse bore of the associate bearing by means oftwo nuts n a, but it may for' the loosening of the inner nut 97. beaxially drawn away from the pump and even be entirely removed from thebearing to permit of the pump being dismounted and examined andcleansed.

On the other end of the journal is there is provided a rotatable arm 0held in place by a nut n and carrying at its free end a pivot 9extending in parallel to the pivot k and having rotatably attached to itthe spinning head I) by means of the hub-shaped head b. The arm 0 andthe pivot g are also provided with channels 10 and which connect thebore of the pivot is with the interior of the spinning head 6.

enses Owing to the'articulated fastenin of the spinning heads at the arm0 whic in its turn is rotatably supported upon the pivot 70, the headmay, if necessary, be lifted ofi' the cylinder 1' of the spinning deviceafter which it is automatically held in raised position by the frictionof the conical transverse bore of the arm 0 upon the conical end of thepivot is.

The provision of the double joint k 9 warrants a good support for, aswell as a reliable tightening of, the flange of the spinning head uponthe upper rim of the cylinder when re-mounting the head upon it.

If the pump is to be dismounted in order to be'inspected, the supply ofcellulose solution is interrupted first by turning the pivot Z whichforms a kind of cock-plug. Thereafterthe inner nut n is loosened and thepivot is shoved to the right so that the pump is free to be removed. Ifthe nut is completely unscrewed, the pivot is may be drawn' out ofthebearing h and maybe removed from the device together with the arm 0 andthe head I) in order to permit of cleansing these parts.

A special advantage of the bored articulated arms 0 consists in thatowing to the supply of the cellulose solution through un-. elastic pipesthe variations are obviated which are experienced with the known spin:ning devices and which are due to the use of rubber hoses between thesupply pipe and the heads, that is to say, to the expansion of the wallsof these hoses, whereby the quantity fed is varied.

In lieu of therotary geared pumpsshown and described, pumps of someother suitable kind may be employed, provided that their output beadjustable exactly and independently of the pressure of the solutionsupplied, so that the supply of exactly determinable quantities of thecellulose solution is permanently warranted.

I claim 1. The stretch-spinning method of manufacturing artificial silkfrom cuprammonium cellulose solutions by expression of the solutionthrough spinnarette apertures of at least 0.8 mm., which consists inconstantly taking from a source of supply of the solution and expressingthrough the spinnarette apertures a fixed volume of the solution perunit of timeconstantly proportionate for a rate of flow through thespinnarette apertures for continually producing filaments of aggregatedimensions when combined. to

, form a thread of continuously predetermined and unvarying diameter,while protecting such volume of solution from pressure variations of thesource, and thensubjectin the filaments to stretch reduction.

2 e stretch-spinning method of manufacturing artificial silk fromcuprammonium cellulose solutions by expression ofthe soluof continuouslypredetermined and unvary-- ing diameter, while protecting the volume ofsolution supplied to each spinnarette from pressure variations of thesource, governing the amount of the solution supplied to eachspinnarette throughout the series so as to apportion like amounts of thesolution at all times to the spinnarettes, and then subjecta ing thefilaments expressed by each spinnarette to stretch reduction.

3. In an apparatus for manufacturing cuprammonium silk by thestretch-spinning. method, a source of supply of cuprammonium cellulosesolution, a spinnarette having a plurality of apertures of at least0.8

mm, a controller operative for constantly feeding from the source ofsupply to the spinnarette and expressing through the spinnaretteapertures a fixed volume of the so lution per unit of time constantlyproportionate for a rate of flow through the spinnarette apertures -.forcontinually producing filaments of aggregate dimensions when combined toform a thread of continuously predetermined and unvarying diameter,while in such feeding action protecting such volume of solution frompressure variations of the source, and means for subjecting theexpressed filaments to stretch reduction.

4. In an apparatus for the manufacture of artificial silk thread by thestretch-spinning method, a supply conduit containing the cuprammoniumcellulose solution, a plurality of spinnarettes each having a pluralityof apertures of at least 0.8,mm., a ro-,

with and operative for feeding from t e conduit to the spinnarette forexpression through the spinnarette apertures a fixed volume of thesolution per unit of time constantly proportionate for a rate of flowthrough the spinnarette apertures for continuallyproducing filaments ofaggregate dimensions when combined to form-a thread of continuouslypredetermined and unvarying diameter, and also operative for protectingsuch volume of solution :from pressure variations of the source, meansfor subjecting the filaments expressed by each spinnarette to stretchreduction, a source ofpower for driving the controllers, and toothedgearing between said source of the. delivery opening of the pump andbe-- pump adapted to feed the spinnarette from that supply pipe, adriving gearing for said pump, this pump being, rockably mounted topermit of throwing the driving gearing into and out of gear, two hollowpivots ar ranged co-axially with the inlet opening and ing adapted toserve as journals for the pump, as well as to connect it on the one sidewith said supply pipe and on the other side with said spinnarette, thepivot connecting the pump with the feed pipe being constructedto form ashut-ofi' cock.

6. In an apparatus for the manufacture of artificial silk from cellulosesolutions after the distending spinning method, a spinning devicecomprising a spinnarette adapted ,to produce comparatively thick threadsadapted to be drawn out to the desired fineness by stretching, a pipefor supplying the cellulose solution, a rotary geared pump for feedingthe spinnarette from said pipe, a driving shaft and cog-wheels fordriving said pump, this latter being so arranged as to be adapted to belaterally moved on an axle lying in parallel to said driving shaft inorder to bring the cog-wheels'out of gear, a clip afiixed to said supplypipe, two projections extending forth from said clip and formingbearings, two hollow pivots supported in these bearings and lyingco-axially with the inlet opening and the discharge connectthe latteron'the'one side with the supply. pipe and on the other side withspinnarette, the pivot efiecting the first of these connections havingan angular channel. adapted to communicate with a channel provided inthe associate bearing and terminating into the feed pipe and having aconical shape and being rotary arranged in a conical bore oftheassociate bearing in order to be able. to serve as shut-off cock.

7. In an apparatus for the manufacture of artificial silk threads fromcellulose solutions after the distending spinning method. a spinningdevice comprising a cylinder adapted to supply a precipitating liquid,adetachable spinnarette resting upon the upper end of said cylinder andbeing adapted to produce comparatively thick threads adapted to be drawnout to the required fineness by stretching, and a funnel arranged insaid cylinder and being adapted to conduct downwards the threads andsaid precipitating liquid, a supply pipe'for the cellulose solution, arotary geared pump for feeding the spin.- narette from said supply pipe,a driving gearing for said pump, this latter being so rockably mountedso as to permit of throwing saidv gearing into and out of gear, two

hollow pivots. arranged, co-axially with the inlet opening and thedelivery opening of the pump and forming journals for it and connectingit on the one side with the said supply pipe and on the other sidewith-the said s'pinnarette, a rotary arm arranged on the pivot effectingthe latter of said connec-' tions, a turning joint connecting said armwith the spinnarette, said joint and the said arm having channelsadapted to connect the channel of said pivotwith the interior of thesaid spinnarette.

'In testimony whereof I aflix my Sig-nature.

MARTIN HoLKEN, J

